Process of making sheets of pyroxylin compound



A 20 flexibility,

addition of castor oil. Thus, in addition to they may be shaved fromthis block by Passes Sept. as, was.

WILLIAM G. LINDSAY, or NEWARK,'NEW JERSEY, nss enoa-mo run CELLULOIDcom- Pamr, A CORPORATION or NEW JERSEY).

\ PROCESS OF MAKING SHEETS OF PYROXYLIN. COMPOUND.

No Drawing. Original application filed'lfebruary 16, 1920, Se'rial No.359,108. Divided and this application filed August 25, 19 22. SerialNo.584,296.

Toallwlwmitvnay concern."

Be it known that I, WILLIAM G. LINDSAY, a citizen of the United States,residing at Newark, in the county of Essex and State of New Jersey, haveinvented certain new and useful Improvements in Processes of MakingSheets of Pyroxylin Compound, .of which the following is aspecification.

The principal object of my invention is to provide a new and improvedcomposition of matter having the quality of flexibility as, well asother desirable qualities. This and other objects of my invention willbe made apparent in the following specification and claims, in which Idisclose certain specific embodiments of theinvention. 'It has beenknown that when it was desired to make a variety ofcelluloid or similarsubstance having a high degree of this end could-be attained by the theusual ingredients in celluloid, namely, nitrocellulose and ca-mphor, amore flexible variety could be obtained by the inclusion therewith of acertain amount of castor oil. On the other hand, compositions obtainedin this way have a number of disadvantages. They may become rancid andsomepreservative has tobe included to counteract this; so also such acomposition including castor'oil is apt to deteriorate rather rapidlyand be come weakand brittle. used to confer flexibility on othercelluloidlike substances, such as a compositiofr of matter obtained bybringing together ina suitable manner nitrocellulose andtricresylphosphate.

I have discovered an improved way for securing flexibility of such amaterial, by which the use of castor oil is entirely avoided and itsdisadvantages are avoided and a superior product is obtained.

Heretofore, in the preparation of a celluloid-like substance fromnitrocellulose and i tricresylphosphate, the proportions used have beenusually about 100- arts of nitrocellulose and to parts 0tricres'ylphosphate. This gives a firm celluloid-like substance when itis molded. Like celluloid it 5 can-'be given an increased flexibility bfthe addition of castor oil. My discovery and improvement involvesgreatly increasing the proportion of trieresylphosphate and not usingany castor oil, The following is Castor oil has been one specificexample of procedure in accordance with my discovery and invention.

I take 100 parts of nitrocellulose and 40 parts of tricmylplhosphate and.unite them in accordance wit the rocedure described .the nitrocelluloseand then work the tricresylphosphate in withit until a pomogeneousplastic mass is obtained. Next,'I extract the moisture and then add asmall proportion of any suitable solvent, such for in my Patent No, 1,23,374, that is, I wet.

homogeneous and-then press it into a solid block. In this form thecomposition is of yielding flexible'character like india rubber. Ifsheets of any thickness are desired,

shaving machines in the same manner as fromcelluloidblocks, or bydissolving the product in volatile solvents flowing and evaporating thesame in the-usual manner.

I may use other proportions of tricresylphosphate. Indeed I secureincreased flexibility with proportions running all the Way fied, but ingeneralI prefer tricresylphosphate because of its superior qualit1esandresulting better product.

V .The substance has manyapplicat ons- By using a large. quantity of sovent it can be obtalned' in liquid form and then brushed upon fabric orother surfaces like a varnish and when the solvent dries out theflexible coating will remain closely adherent to the surface. It can bemolded and pressed into.

various desired shapes. Blocks of this composition may be used forcushlon buffers; By using a suitable fabric and suitable thickness ofthe material herein described and claimed, I can produce superior"varieties of so-called artificial leather and the surface can'bestamped in imitation of mor GOQ 0r allig or or in any other say /1000 to1/100 of an inch in thickness, may be laid on closely woven cottonfabric, that has been brushed pver with the solvent. Upon application of5 pressure, together with heat the sheet of the substance is intimatelyunited to the fabric. The result isa highly flexible water-proof.fabric. It can be crumpled up compactly in the hand without acquiringany set and without breaking the coating. These are "only a fewsuggestions of the many uses-to which the improved material may be put.In addition to flexibility my improved way Thin sheets,

composition has other advantageous qualities as follows: It is much moredurable than those celluloids or celluloid-like substances which havebeen made flexible by the addition of castor oil; it isvflaterproof andalso not easily inflammable and the difliculty of igniting it increaseswith the proportion of tricresylphos'phate so that, for instance, with300 parts tricresylphosphate to 100 parts pyroxylin the product issubstantially non-inflammable. Theingredients are comparativelyinexpensive and "the process of uniting them .is not expensive so thatthe material may be cheaply produced.

This case is division of my application, Serial No. 359,108, forimprovement in pyroxylin compound and process of making same, filedFebruary 16, 1920. i

I claim 1. In the method of making a sheet of permanently flexiblematerial'the ste s which consist in working upon rolls a mixture ofapproximately 100 parts of nitrocellulose and upwards of 60 parts of anaromatic phosphate, then pressing the mass into a solid block,

and'then shaving a sheet therefrom.

2. In the methodv of making'a sheet of permanently flexible whichconsist in working upon rolls a mixture of approximately 100 parts'ofnitrocellulose and upwards of 60 parts of a tricresylphosphate, then.pressing the mass into a solid block, and then shaving a sheettherefrom. v

3. The method of making a sheet bf permanently flexible material whichconsistsin working upon rolls in the presence of a mutualvolatilesolvent a mixture of approximately 100 parts of nitrocelluloseand upwards of 60 parts of an aromatic phosphate, then pressing the massinto a solid block, and then shaving a sheet therefrom.

4. The process of forming flexible sheets which consist in shaving saidsheets from a block of rubber-like consistency formed of 100 parts of acellulose ester and in excess of parts of an aromatic ester.

5. In the method of making a sheet ofpermanently flexible material, thesteps which consist in working together nitrocellulose and an aromaticphosphate in the presence of water, extracting the water, working intothe mass additional phosphate, pressing the mass intoa solid'block 03frubber-like consisteneyand shaving sheets from said block.

WILLIAM G. LINDSAY.

material the steps 7

